The present invention is directed to a process for producing one or more colored filaments from a spinneret by dissolving dyes or coloring matter into the polymer flow upstream of the spinneret face but downstream of any extruder.
In the prior art, polymers may be dyed or colored by uniformly introducing the desired pigments or dyes into the polymer during polymerization. A dye concentrate may also be introduced into molten polymer by mixing the two components together and extruding the mixed components for flow to a spinneret. Still another method may involve introducing a concentration with the pelleted polymer feed in an extruder. In any of these methods the entire system must be thoroughly cleaned, including extruders and any conduits leading between the extruder(s) and the spinneret when it becomes necessary to make a color changeover in order to avoid color contamination.